Cover googletagmanager-gtm functionality by google-analytics #127

Details - https://ilakovac.com/teespring-ublock-issue/
and - gorhill/uBlock@8cd2a1d

Steps to reproduce:

1. Add this rule:
   ||googletagmanager.com/gtm.js?$third-party,script,redirect=googletagmanager-gtm
2. Go here - https://bela.gifts/listing/fali-cetvrti-tamna?product=1303
3. Click on "Add to cart" button and then on "Proceed to checkout".

Expected behavior

"Proceed to checkout" should works.

Actual behavior

Button doesn't work.